leaking fuel rail cap fix

83859 Views 67 Replies 22 Participants Last post by atoman, Jan 14, 2017

blknblu

Discussion Starter · May 19, 2012

First time posting,
I have a 2001 Chrysler Town Country with 3.8

For several months now, I've detected a strong smell of gas under the hood. After watching it for a couple of days, I noticed gas dripping out of the cap on the fuel rail. I found a post where someone removed the cap and replaced the internal o-ring with an o-ring from the fuel injectors. (Same size) I did the fix, and it has not leaked since I replaced the o-ring. The best part was I did not have to remove the fuel rail. (A new one is pricey) You will need to go to the auto store and ask for fuel injector o-rings for the van. Mine came in a package of 2 for 2.39 from NAPA.

Thse are the steps I took:

1) Relieve gas pressure from fuel injection rail:
Remove the fuel pump relay and start the van, running it until it dies. (The relay is in the fuse box)

2) disconnect the battery (just being cautious)

3) Move power steering reservoir:
Loosen the bolts for the reservoir , lift it slightly and push it to the side.
(There are 2 accessible bolts on the top, and one nut underneath that you just have to loosen)

4) Remove cap:
Gently pry the cap off, use the bracket for the power steering for leverage.

The pic with the blue o-ring is the original. (notice the erosion on it)

5) Prepare cap:
Remove old o-ring
Bend the tangs back on the cap so it will fit tightly when you re-install it.
Lubricate the o-ring with some fresh oil and put it on the cap.

6) Install cap:
Put cap over the hole making sure it is centered.
Gently tap on the end until it slides back in the hole and is seated properly.

7) Check for leaks:
Re-connect the battery.
Put back the fuel pump relay and start van.
Check for leaks.

8) Put everything back together:
Move power steering reservoir back and tighten bolts.

That's it, it is pretty simple to do as long as you are careful.
Not once did the CEL come on.
This cap is not for a test port, it looks more like a pressure relief port.

See less See more

Save

Reactions: 5

61 - 68 of 68 Posts

atoman

· #61 · Jun 3, 2016

that diaphragm must be under the hammer

In most plumbing systems, fluid dynamics of inertial velocity are handled with a gas (mostly air) dampening (say that 3x fast).
Most likely the cap maintains an air bubble near the end of the fuel rail, the redesigned rails simply leave the cap out (are sealed).

Save

blknblu

Discussion Starter · #62 · Jun 3, 2016

As far as I can remember, there was nothing in the hole with the cap off.
The leak was caused by a bad o-ring.
the cap had fingers to secure it in place.
Very simple really, and as long as you were careful taking it apart, it went back together fine.

See less See more

Save

ramby

· #63 · Jun 6, 2016

My cap was still leaking. It is really a very slow seeping or wetness on the cap at a very slow pace. I decided to remove it to inspect the o ring. It may be the o ring or the seam under the cap where the clips are. No matter because I epoxied the entire cap in place right down to the rail. As of last week I have no more leak or smell of gas. If my $4 fix holds I am happy. I am not spending $140 or more on a 15 year old van with 212k on it. I know tomorrow I will have my next cheap fix to think about. My experience tells me if I reach 275k miles and the van is 20 years old, I am driving it to the bone yard or having it towed. I am on my 8th van and have been buying some new and some old since 1991. I own 3 of them right now. No matter how much money I spend on new parts the rust ( cancer) will make all those new parts a very bad investment if they are bought near the end of the vans life. Right now my van is in stage 3 cancer so I chose to spend only $4. If I spring a leak again I will post it here and then buy a new rock auto fuel rail maybe. I have been driving for 50 years and it is always the cancer that ends my vehicle's life. I always feel very sad when my engine and tranny are still in great shape but they have been shortchanged by a rusty frame and body. Last year I lost 3 vehicles. My van cracked a rear axle and my dodge shadow dropped a coil spring due to corrosion. Only 130k miles on the shadow but it was over 20 years old. You have to know when to hold um and when to fold um.

See less See more

Save

itsallgood

· #64 · Jun 7, 2016

ramby said:
My cap was still leaking. It is really a very slow seeping or wetness on the cap at a very slow pace. I decided to remove it to inspect the o ring. It may be the o ring or the seam under the cap where the clips are. No matter because I epoxied the entire cap in place right down to the rail. As of last week I have no more leak or smell of gas. If my $4 fix holds I am happy. I am not spending $140 or more on a 15 year old van with 212k on it. I know tomorrow I will have my next cheap fix to think about. My experience tells me if I reach 275k miles and the van is 20 years old, I am driving it to the bone yard or having it towed. I am on my 8th van and have been buying some new and some old since 1991. I own 3 of them right now. No matter how much money I spend on new parts the rust ( cancer) will make all those new parts a very bad investment if they are bought near the end of the vans life. Right now my van is in stage 3 cancer so I chose to spend only $4. If I spring a leak again I will post it here and then buy a new rock auto fuel rail maybe. I have been driving for 50 years and it is always the cancer that ends my vehicle's life. I always feel very sad when my engine and tranny are still in great shape but they have been shortchanged by a rusty frame and body. Last year I lost 3 vehicles. My van cracked a rear axle and my dodge shadow dropped a coil spring due to corrosion. Only 130k miles on the shadow but it was over 20 years old. You have to know when to hold um and when to fold um.

I totally understand. I had to make the same decision as you, on our 15 yrs old van. We have some body rust on the outer door panels and rear dog legs. Our van has over 187K now and I decided to give new life to our van by cutting out the rust and welding in new sheet metal. It is time consuming and requires a lot of patients. But, it will all pay off in the long run. The most major repair we've had so far is to replace the torque converter. (Which I'm in the process of doing now.) The inside of our van still looks really good with no rips, tears, cracks or stains. (After raising 5 kids) So for me, it was a no brainier. Mechanically, she should be good for another 100K without any major repairs. had an oil analysis done around 7K ago and the engine is very healthy and wearing below the standard. I do 95% of the maintenance myself, so the cost of repairs are minimal. We do have a second car to drive around if I can't finish the fix on time.

Save

jcw56

· #65 · Jan 12, 2017

Jim

Same problem here.
But cap on rail does not want to come off.
Should I just use more force?
If the cap is a safety pressure-release valve, why does mine leak only when the engine is running COLD?
Love to have your and others' thoughts on this.

Save

wayneh

· #66 · Jan 13, 2017

It's not a release valve, it's a damper to absorb pressure spikes caused by the sharp open/close of the injectors.

More force will get it off, and that's about your only option if the rail is still on the car. If you get the rail onto your workbench, you might work a small tool up under the cap to disengage those clips.

But removing the cap and attempting to repair it may be a lost cause. I'd guess the odds of success are 50% or less. The other 50% (like me) end up buying a new rail and wishing they had done that at the start.

The problem is achieving a good seal again once you've muscled that cap off. The spring clips get bent and don't function properly. I tried holding the cap down with a cable tie, which worked for a while. Smothering the cap's bottom and the fuel rail stem in JBWeld worked much longer but eventually failed. I could have done a better job and maybe it would be permanent, but maybe not. Expansion/contraction with heat is a problem.

Save

blknblu

Discussion Starter · #67 · Jan 13, 2017

Just have to be patient with it.
Here it is ..

See less See more

Save

atoman

· #68 · Jan 14, 2017

IDK what the springs clip onto on the rail, but if you cut a strip of plastic or metal (from say a beer/soda can) just wide enough to fit under the clips on the stem on the rail and wrap it around the rail stem a few times to build up the thickness, then slide it up the stem with a pick or screwdriver - it should buy you enough thickness to 'retract' the clips and remove the cap intact. Some experimentation / several attempts may be needed (be patient, go slow).

Save

61 - 68 of 68 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.

Top Contributors this Month